1 /* vmparam.h 1.2 86/01/05 */ 2 3 /* 4 * Machine dependent constants for TAHOE 5 */ 6 /* 7 * USRTEXT is the start of the user text/data space, while USRSTACK 8 * is the top (end) of the user stack. LOWPAGES and HIGHPAGES are 9 * the number of pages from the beginning of the P0 region to the 10 * beginning of the text and from the beginning of the P2 region to the 11 * beginning of the stack respectively. 12 */ 13 #define USRTEXT 0 14 #define USRSTACK (0xc0000000-UPAGES*NBPG) /* Start of user stack */ 15 #define BTOPUSRSTACK (0x300000 - UPAGES) /* btop(USRSTACK) */ 16 #define P2PAGES 0x100000 /* number of pages in P2 region */ 17 #define LOWPAGES 0 18 #define HIGHPAGES UPAGES 19 20 /* 21 * Virtual memory related constants, all in clicks 22 */ 23 #define MAXTSIZ (6*CLSIZE*1024) /* max text size */ 24 #ifndef DFLDSIZ 25 #define DFLDSIZ (6*1024*1024/NBPG) /* initial data size limit */ 26 #endif 27 #ifndef MAXDSIZ 28 #define MAXDSIZ (19*1024*1024/NBPG) /* max data size */ 29 #endif 30 #ifndef DFLSSIZ 31 #define DFLSSIZ (512*1024/NBPG) /* initial stack size limit */ 32 #endif 33 #ifndef MAXSSIZ 34 #define MAXSSIZ MAXDSIZ /* max stack size */ 35 #endif 36 37 /* 38 * Default sizes of swap allocation chunks (see dmap.h). 39 * The actual values may be changed in vminit() based on MAXDSIZ. 40 * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024. 41 */ 42 #define DMMIN 32 /* smallest swap allocation */ 43 #define DMMAX 4096 /* largest potential swap allocation */ 44 #define DMTEXT 1024 /* swap allocation for text */ 45 46 /* 47 * Sizes of the system and user portions of the system page table. 48 */ 49 /* SYSPTSIZE IS SILLY; IT SHOULD BE COMPUTED AT BOOT TIME */ 50 #ifdef notdef 51 #define SYSPTSIZE ((20+MAXUSERS)*NPTEPG) 52 #define USRPTSIZE (32*NPTEPG) 53 #else 54 #define SYSPTSIZE ((128*NPTEPG/2)+(MAXUSERS*NPTEPG/16)) 55 #define USRPTSIZE (4*NPTEPG) 56 #endif 57 58 /* 59 * The size of the clock loop. 60 */ 61 #define LOOPPAGES (maxfree - firstfree) 62 63 /* 64 * The time for a process to be blocked before being very swappable. 65 * This is a number of seconds which the system takes as being a non-trivial 66 * amount of real time. You probably shouldn't change this; 67 * it is used in subtle ways (fractions and multiples of it are, that is, like 68 * half of a ``long time'', almost a long time, etc.) 69 * It is related to human patience and other factors which don't really 70 * change over time. 71 */ 72 #define MAXSLP 20 73 74 /* 75 * A swapped in process is given a small amount of core without being bothered 76 * by the page replacement algorithm. Basically this says that if you are 77 * swapped in you deserve some resources. We protect the last SAFERSS 78 * pages against paging and will just swap you out rather than paging you. 79 * Note that each process has at least UPAGES+CLSIZE pages which are not 80 * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this 81 * number just means a swapped in process is given around 25k bytes. 82 * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81), 83 * so we loan each swapped in process memory worth 100$, or just admit 84 * that we don't consider it worthwhile and swap it out to disk which costs 85 * $30/mb or about $0.75. 86 */ 87 #define SAFERSS 32 /* nominal ``small'' resident set size 88 protected against replacement */ 89 90 /* 91 * DISKRPM is used to estimate the number of paging i/o operations 92 * which one can expect from a single disk controller. 93 */ 94 #define DISKRPM 60 95 96 /* 97 * Klustering constants. Klustering is the gathering 98 * of pages together for pagein/pageout, while clustering 99 * is the treatment of hardware page size as though it were 100 * larger than it really is. 101 * 102 * KLMAX gives maximum cluster size in CLSIZE page (cluster-page) 103 * units. Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h. 104 */ 105 106 #define KLMAX (32/CLSIZE) 107 #define KLSEQL (16/CLSIZE) /* in klust if vadvise(VA_SEQL) */ 108 #define KLIN (8/CLSIZE) /* default data/stack in klust */ 109 #define KLTXT (4/CLSIZE) /* default text in klust */ 110 #define KLOUT (32/CLSIZE) 111 112 /* 113 * KLSDIST is the advance or retard of the fifo reclaim for sequential 114 * processes data space. 115 */ 116 #define KLSDIST 3 /* klusters advance/retard for seq. fifo */ 117 118 /* 119 * Paging thresholds (see vm_sched.c). 120 * Strategy of 1/19/85: 121 * lotsfree is 512k bytes, but at most 1/4 of memory 122 * desfree is 200k bytes, but at most 1/8 of memory 123 * minfree is 64k bytes, but at most 1/2 of desfree 124 */ 125 #define LOTSFREE (512 * 1024) 126 #define LOTSFREEFRACT 4 127 #define DESFREE (200 * 1024) 128 #define DESFREEFRACT 8 129 #define MINFREE (64 * 1024) 130 #define MINFREEFRACT 2 131 132 /* 133 * There are two clock hands, initially separated by HANDSPREAD bytes 134 * (but at most all of user memory). The amount of time to reclaim 135 * a page once the pageout process examines it increases with this 136 * distance and decreases as the scan rate rises. 137 */ 138 #define HANDSPREAD (2 * 1024 * 1024) 139 140 /* 141 * The number of times per second to recompute the desired paging rate 142 * and poke the pagedaemon. 143 */ 144 #define RATETOSCHEDPAGING 4 145 146 /* 147 * Believed threshold (in megabytes) for which interleaved 148 * swapping area is desirable. 149 */ 150 #define LOTSOFMEM 2 151 152 /* 153 * BEWARE THIS DEFINITION WORKS ONLY WITH COUNT OF 1 154 */ 155 #define mapin(pte, v, pfnum, count, prot) \ 156 (*(int *)(pte) = (pfnum) | (prot), mtpr(TBIS, ptob(v))) 157 158 /* 159 * Invalidate a cluster (optimized here for standard CLSIZE). 160 */ 161 #if CLSIZE == 1 162 #define tbiscl(v) mtpr(TBIS, ptob(v)) 163 #endif 164 165 /* 166 * The following constant is used to initialize the map of the 167 * system page table i/o entries. 168 * It's value should be the highest i/o address used by all the 169 * controllers handled in the system as specified in ubminit 170 * structure in ioconf.c. 171 */ 172 #define MAXIOADDR 0xffffee45 173 /* number of entries in the system page pable for i/o space */ 174 #define IOSIZE (((MAXIOADDR - (int)IOBASE+ NBPG-1) >> PGSHIFT)+1) 175 #define TBUFSIZ 32 /* maximum tape buffer size */ 176 #define ACEBPTE 32 /* ACC Ethernet (ACE) I/O window */ 177